Gastrinomas are the most common symptomatic, malignant PET in patients with or without MEN1 and sufficient numbers of these patients have been entered into our protocols to allow systematic assessment. Studies are now underway, evaluating the natural history of these tumors including the presentation and initial diagnosis and definition of factors determining prognosis. Our studies have identified a cohort of 25% of patients in whom the gastrinomas have aggressive growth and 25% who have multiple endocrine neoplasia type 1 (MEN1). During this year a prospective study of surgical treatment of hyperparathyroidism in MEN1 patients was completed showing that they have more severe disease than occurs in patients with MEN1 without gastrinomas;a prosepctive study of the occurrence of gastric carcinoids in MEN1/ZES patients was complete establishing the incidence of these tumors in these patients and recommending appropriate followup and prognostic factors for their presence, and a number of consensus conferences and position papers on treatment of various disease aspects were published.